About Air Circulation in Airplanes

Cabin air is renewed with fresh air every 2-3 minutes.


Fresh external air constantly replaces the cabin air every 2-3 minutes.


Modern aircraft are fitted with highly proficient air filters* keeping the cabin air clean at all times.

  • High-Efficiency Particulate Air (HEPA) filters are 99.97% effective at removing virus, bacteria, and fungi measuring 0.3μm in diameter, including the Coronavirus.


Air in a cabin flows from top to bottom and is fully renewed.

Flow of the air using HEPA filter image

  1. The aircraft receives external air through the engine
    *The Boeing 787 uses electric compressors to feed external air directly into its air-conditioning system, rather than from the engine.
  2. The air-conditioning system adjusts the compressed air to an appropriate temperature and supplies the clean air throughout the cabin.
  3. The differential pressure will push the air inside the cabin toward the belly of the aircraft and is discharged from the cabin pressure control valve.
  4. For the ATR turboprop aircraft operated by Hokkaido Air System and Japan Air Commuter, fresh air replaces the cabin every 4-6 minutes. As for the SAAB340B aircraft operated by Hokkaido Air System, fresh air replaces the cabin every 4-5 minutes. Both aircraft are not equipped with HEPA filters but the ventilation system allows fresh air to be supplied from the overhead compartment and extracted at the bottom of the aircraft.

August 6, 2020

Japan Airlines